Method of making artificial cork



Nav. 16 1926.

L. L. BENTLEY METHOD OF MAKING ARTIFICIAL CORK Original Filed June 15. 1921 Patented `Nov. I6, 1926. v

UNITED STATES PATENT OFFICE.'

LoUIs L. BENTLEY, oF BEAVER FALLS, PENNsYLvAN1A,'Ass1GN0R T5 ARMSTRNG CORK COMPANY, or PITTSBURGH, PENNSYLVANIA, A CORPORATION oF PENNSYL- VANIA.

' METHOD oF MAKING ARTIFICIAL CORK.

Application led June 15. 1921, Serial No. 477,747.v4 Renewed'Febrliary 1.9, 1926. i

My invention' has relation to the treatment of artificial cork, and more particularly to the manufacture of shaped bodies from cork particles or'granules. f

It has been common practice heretofore to make cork bodies of the character above stated by compressing the 'cork particles in suit-able molds, and then placing themoldsI in a baking oven and subjecting them to heat while retaining the cork mass under compression. It has also been proposed to effect the heating of the cork by the use of super-heated steam; and in the co-pending Y application filed by Leonard W. Bertelsen,

Jr., Serial No. 477 ,748 there is described and:

claimed 'a met-hed of using steam for this purpose in which the steam is passed through the mass of compressed cork.

I have discovered that a more eliicient action may be obtained by the use of a. heating medium'of a nature to cause a chemical reaction on the cork, this reaction being of as character to materially increase the temperature in the mass under treatment, above the temperature of the heating medium used. I am not prepared at this time to fully state the nat-ure of this exothermic reactionfbut it is of an oxidizing character; and the medium employed should contain sucient oxygen to produce such. a lreaction. The mediumv which I have heretofore employed with good results, is hot air, although furnace gases, or a mixture of air and steam may be employed. I have obtained good results by 220 to 310 C. supplyingfrom 35 to 40 'cubic feet `per minute of such air to each.

square foot of area ofthe cork mass being treated. Usually from 30 to 35 minutes is required for the treatment. The mass is then allowed to cool in the mold.

In the..Y accompanying drawing I- have shown one form of apparatus which may be employed in carrying out my invention. In this drawing'the numeral 2 designates a mold body into which the mass of cork to be treated is compressed and by which it is shaped. The mass is held under compression between thel erforated bottom plate 3 and the perforated top plate 4 by any suitable means, such as the keys 5. These perforated top and bottom plates are preferably of two thicknesses, having perforations of different sizes. The hot air or furnace gases,

heated air of a temperature vof from I.

operation of baking in ovens.

or the mixture of air and steam is supplied from any .suitable source by means of a pipe 6 terminating in a funnel 7 vwhich forms aseat Ior a flange 8 on the'lower end of the mold body, a packing or gasket 9 being interposed between the two flanges. The mold body also has the perforated internal flange l0 forming a support for the bottom mold plate. The hot gases escaping from the mass may pass into-the open air or they may be collected by a removable inverted top funnel l1 having an -oiitake pipe l2. If desired, this pipe 12 may be connected with a. fan which will return the air andk gases to a heater' in which' they can be reheated and then supplied under pressure to the bottom funnel for re-use. 1n some 1nstances, this is advisable, as such regeneratedl air and gases contain less oxygen" than .does atmospheric air, and a less strong reaction occurs within the cork mass.

I have proven 'thefact of the reaction by inserting temperature measuring means at dilIerent portions of the cork mass during than the temperature of the heating medium upon its entrance into the cork mass.

The completion of the operation canbe `determined by temperature measuring devices inserted in the mass, or `by observing the colorand character of, the escaping gases.

My invention provides a practical commercial method of making shaped articial cork bodies with comparativel small expense. The'time requiredto e ect a treatment is very much shorter than the old It is also shorter than the time required to elect the treatment by the use of super-heated steam. Furthermore, the reaction which is produced within the cork is extremely effective in causing the expansion and binding ofthe particles together, the result bein a shaped body which possesses a considera le degree of homogeneity and which has'considerable structural strength. e

I do not limit myself to the use of any 'y roo carried out by the use of various forms of apparatus.

v.The time required for the operation mayl be somewhat shortened by pre-heating the cork articles, but this I do not -ordinarily consi er, advantageous, as it requires rate partial-heating operation- 1. The herein described` method of' treating cork particles which consists in passing through `a mass of such .particles while held under applied compression mdependently of any heatlng medium, a heating medium of a character which willproduce an eXothermic reaction-Within the cork mass, substantially as described., Y A 2. The herein described .method of treat.

ing cork particles which consists in applying pressure yto the same in a mold, vand passing vtherethrough While under compression a heating medium of a nature to cause an exothermic reaction to take place Within `the mass of cork particles, substantially as described.

3. The herein described method of forming shaped artificial cork bodies which con-A sists'in passing a heated oxygen-containing medium through a mass of cork particles Vwhile held under applied compression by a mold, substantially as described.l

et. The hereindescrihed method of forming shaped artificial. cork bodies which consists in passing aheated oxygen-containing medium through a pre-compressed mass of cork particles, substantially as described.

5. The herein described method of forming shaped bodies of artificial cork which consists in charging a mass of cork particles into a shaping receptacle, separately conipressing the particles therein, holding the compressed mass under compression, and

a sepa-` passing a heating medium therethrough lof* a character whichvwill producea heat reaction Within' the mass, substantially 'as described. f

' 6. The herein described lmethod of making shaped artificial cork bodies which consists in initially compressing a mass of cork particles in asha in receptacle, and passing 4 hot air througi t e mass While holding it under 4such applied compression, substanl passing hot air pressing the preheated particles in a suit` able mold, and thereafter passing an oxygen-contalning heating medium through the mass While it is still under compression, substantially as described.

.9. The herein described method of making shaped artificial cork bodies, Which consists in preheating a mass of cork particles, compressing the preheated particles in a suitable mold, andthereafter passing hot air through themass While it is still under compression. substantially ,as described.

In 'testimony whereof, I have hereunto set my hand.

LOUIS L. BENTLEY. 

